The invention relates to a follower for holding a window pane which can be adjusted by means of a vehicle window lifter.
A follower of this kind is known from DE 4434589 A1. The known follower comprises a pair of elastically expanding jaws, which are connected to the base body of the follower. In order to insert a window pane into the follower the jaws are spread apart. After inserting the window pane the jaws move back to adjoin same; they thereby come into keyed engagement with a hole in the window pane or a positive locking element fixed on the window pane.
The drawback with the known follower is that if larger forces occur in the lifting direction of the window, for example in the event of a crash, the jaws of the follower are inclined to spread open. There is then the risk of the window pane coming out of the follower.
From EP 0 643 188 A1, a follower is known for a motor vehicle window lifter having a fixed part and a movable part fixed thereon. The movable part is fitted on the fixed part by swivelling the movable part about a swivel point of the fixed part and then sliding the movable part along the fixed part. This produces a positive and force-locking connection between the fixed and movable parts of the follower. The movable part has a retaining arm which adjoins a surface of the window pane which is to be taken up by the follower and engages with a projection through an opening in this window pane. In its functioning position (i.e. after fitting the movable part on the fixed part), this retaining arm is mounted so that when a removal force acts on the window pane having a tendency to loosen the window pane from the follower the retaining arm is swivelled in a direction away from the associated surface of the window pane.
From EP 0 694 669 A1 a device is known for connecting a window pane to a window lifter (follower) where a pair of clamping jaws are pressed in the region of a window pane edge through a tensioning force onto each one side of the window pane. The formation of this follower is such that the clamping jaws are inclined to spread out when a removal force acts on the window pane.
The object of the invention is therefore to provide a follower of the kind mentioned at the beginning which can also hold the window pane secure even when large forces arise in the lifting direction of same.
According to this, it is proposed to design the follower so that if the window pane is loaded with a removal force that has the tendency to loosen the window pane in the lifting direction out from the follower, a torque acts on the follower to press the at least one retaining arm of the follower, which is located in engagement with the window pane, in the direction of the window pane surface. This is possible in particular through a suitable design and binding of the retaining arm on the base body of the follower.
The invention is based on the surprising knowledge that securing the window pane from sliding out of the follower can be undertaken without any expensive additional structural elements by using the force which acts on the window pane and which threatens to loosen the pane, to strengthen the connection between the window pane and follower. This is based on the same underlying principle as in the case of scissors, where the cutters are closed when they hang down vertically by their handles.
The solution according to the invention has the advantage that as a result of the stressed design of the follower, the force by which the pane is held in the follower becomes greater the greater the force which acts on the window pane in the lifting direction. For it is the latter force which produces the torque through which the follower is pressed towards the surface of the window pane in order to strengthen the connection.
The window pane is therefore held securely in the follower up to very high removal forces. The limit lies only at those forces which would lead to a destruction of the follower.
In a preferred embodiment of the invention, the holding arm of the follower is able to swivel substantially across the plane of the window pane and can thereby be brought into positive locking engagement with the window pane.
The positive locking engagement can be produced in particular if the retaining arm has a stop which is supported on a counter surface of the window pane so that the window pane is prevented from sliding out from the follower in the lifting direction.
With this embodiment of the invention, the follower is designed so that the swivel movement of the retaining arm corresponds substantially to a movement about an imaginary swivel area which, as seen from the section of the retaining arm running along the window pane, is arranged behind a plane which runs through a force engagement point of the stop at the counter surface and parallel to the displacement plane of the window pane.
The swivel area can thereby be formed both by a conventional swivel axis and by a section of the follower with reduced material thickness.
It can thereby be proposed that the retaining arm has a connecting section which, as seen from the section of the retaining arm running along the window pane, is connected to the base body of the follower behind the aforementioned plane.
If the follower is provided in the conventional way for holding the window pane in the area of the lower pane edge then the connecting section of the retaining arm underneath the lower edge of the pane can be supported on the base body of the follower.
The retaining arm underneath the lower edge of the pane can thereby be supported on a counter member of the follower so that it can swivel about this counter member. Furthermore the retaining arm is preferably hung from the counter member of the follower secured against loss.
The stop at the upper end of the retaining arm of the follower is preferably formed as a hooked element which projects into an opening of the window pane associated with same or is supported on a counter face protruding from the window pane. This counter face can be formed on one side by a structural element which is pushed into an opening of the window pane or by a structural element which is stuck onto the window pane.
The follower can have on the side opposite the retaining arm a rigid follower section which adjoins the window pane. As an alternative, the follower can have two retaining arms which can be brought into engagement with opposing side faces of the window pane, wherein each retaining arm is formed so that when the window pane is loaded with a force in the lifting direction a torque is exerted on the retaining arm which presses it towards the surface of the pane.
In a preferred embodiment of the invention the two retaining arms of the follower criss-cross one another and thereby form a U-shaped socket for the lower edge of the pane.
The retaining arm itself is preferably made of an elastically deformable material and is connected for swivel or bending movement to the base body of the follower.